#define _CRT_SECURE_NO_WARNINGS 1
#include <cmath>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include<math.h>
#include<stdlib.h>
#include<stdio.h>
#include<unordered_map>
using namespace std;

class Solution {
public:
    string modifyString(string s) {
        int n = s.size();
        for (int i = 0; i < n; i++)
        {
            if (s[i] == '?')
            {
                for (int j = 0; j < 26; j++)
                {
                    if ((i == 0 || s[i - 1] != 'a' + j) && (i == n - 1 || s[i + 1] != 'a' + j))
                    {
                        s[i] = 'a' + j;
                        break;
                    }
                }
            }
        }
        return s;
    }
};

int main() {
    return 0;
}